More generally, superconducting circuit QED is a particularly promising platform for experiments in quantum optics and quantum physics generally due to its flexibility and readily available set of microwave tools. Possible applications include exploring the ultra/deep-strong coupling regimes of light-matter interaction [1]}, [2]}, [3]}, interaction with non-Ohmic environments [4]}, [5]}, [6]} and cooperative effects [7]}, [8]}, see also review [9]}.
Furthermore, by using the superconducting circuit QED platform we are taking advantage of quantum limited parametric amplifiers. These, or similar devices, have become a standard part of any experimental circuit QED setup. In particular they add very little noise to the amplified signal: reduced to the input noise can be as low as half of a photon in terms of added noise number [10]}. In our setup we are using an amplifier known as Josephson Parametric Converter (JPC)[11]}. The limited amplification bandwidth of a JPC (\(\sim \) 5 MHz), which in many cases can be considered as a drawback, allows to effectively Fourier filter the single photon signal.
